Substituent-Controlled Regioselective Photoinduced Cyclization of N-Allylbenzamides with N-Sulfonylaminopyridinium Salts

Org Lett. 2023 Jan 27;25(3):494-499. doi: 10.1021/acs.orglett.2c04190. Epub 2023 Jan 12.

Abstract

The annulation reactions of N-allylbenzamides with N-sulfonylaminopyridinium salts were developed under metal-free photoinduced mild conditions. Substituent-controlled sulfonaminoarylation and sulfonaminooxylation of benzamides were realized: N-allylbenzamides lead to benzosultams, while N-(2-phenylallyl)benzamides give sulfonamidylated oxazoline derivatives. Control experiments indicated that those reactions undergo a radical pathway with arylsulfonamidyl radicals as the intermediates. The aryl C-H bond functionalization in arylsulfonamidyl was involved for the first time to give benzosultams.